Heating apparatus

ABSTRACT

A heating apparatus for simultaneously heating a substrate and the under surface of a path to be applied to the substrate in conjunction with means for applying the patch under pressure to a substrate.

United States Patent Captain et al.

HEATING APPARATUS Inventors: Khushroo M. Captain, Cambridge,

Mass; John H. Edwards, Warwick, R.I.; David B. Russell, Ashland, Mass.

American Velcro, Inc., New York, NY.

Filed: Aug. 10, 1971 Appl. No.: 170,611

Assignee:

US. Cl 56/499, 156/285, 156/322, 219/345 Int. Cl. .l B296: 19/02 Fieldof Search 156/285, 322, 499; 219/345 References Cited UNITED STATESPATENTS 5/1966 Huddleston 156/499 Nov. 20, 1973 FOREIGN PATENTS ORAPPLICATIONS 2,012,716 10/1970 Germany 156/499 Primary raminerllaroldAnsher Assistant Examiner-M. E. McCamish Attorney-Dean S. Edmonds et a1.

[5 7 ABSTRACT A heating apparatus for simultaneously heating a substrateand the under surface of a path to be applied to the substrate inconjunction with means for applying the patch under pressure to asubstrate.

4 Claims, 5 Drawing Figures rump Patented Nov. 20, 1973 3,773,597

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2 Sheets-Sheet 1 FIG. 2

Patented Nov. 20, 1973 3,773,597

2 Sheets-Sheet 2 HEATING APPARATUS BACKGROUND OF THE INVENTION Thepresent invention relates to improvements in patch applicator apparatusof the type which apply sections of hook or loop fastener tape to a webor substrate. An example of such an apparatus may be found in co-pendingSer. No. 134,816, filed Apr. 16, 1971, by the assignee of thisapplication, which is incorporated by reference herein. Such apparatusobviates the necessity of attaching tape sections by sewing or othermechanical fastening means and instead quickly bonds a tape section to asubstrate by heat and pressure. Where the substrate is relativelypermeable to heat transmission, it is possible to provide a source ofheat beneath the substrate which will penetrate through to the adhesivecoating upon the under surface of the tape when the tape has beenpressed ionto the substrate. However, it has been found that this methodis inefficient or unworkable for certain substrate materials, forexample where such materials are impermeable to the transmission of heator where the thickness of the substrate makes such transmissioninefficient and slow.

The present invention provides an improved heating means for use inconjunction with a patch applicator of the above type which worksequally well with heat permeable or impermeable substrates.

SUMMARY OF THE INVENTION In accordance with the present invention, thereis provided in combination with a patch applicator, a heating elementand means for interposing such element between the patch applying headand the substrate to which the patch is to be applied. The heatingelement in this position will rapidly condition a suitablethermally-responsive coating upon the under surface of the patch and theupper surface of the substrate for adhesive pressure bonding of thepatch to the substrate. Means are further provided for withdrawing theheating element immediately prior to application of the patch underpressure to the substrate. One aspect of the invention involves the useofa head which holds the patch against its under surface by means ofvacuum pressure. In accordance with such concept, the heating element isconstructed to provide a maximum radiant heating area and a minimuminterruption of heating area to inhibit the flow of air to the patchholding head, thereby to minimize cooling of the adhesive.

These and other aspects of the invention will be described in connectionwith the following detailed specification and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF A PREFERRED EMBODIMENTReferring now to the drawing and initially to FIGS. 1 and 2 thereof,there has been illustrated a patch applicator apparatus 10. Theapparatus has a vertical frame 10a and a base 10b. A substrate 12 isarranged upon the base 10b for the application thereto of a patch 13applied under pressure by an applicator head 14 which holds the patchprior to and during application. In the particular embodiment, the patch13 is a section of hook or loop fastener tape and the substrate 12 isrelatively thick heat impermeable material. The undersurface of patch 13is coated with a suitable adhesive which is subjected to heat by theapparatus of the invention prior to the application of the patch to thesubstrate. The head 14 is hollow and defines in its lower surface 14a aseries of apertures 14b. A vacuum is created within the head 14 by ameans (not shown) such that a suction force will be applied to the uppersurface of the patch 13 to hold it in place against the lower surface14a of the head.

Head 14 is moved between upper and lower positions by operation ofcylinder 16 attached to frame 10a whose actuating rod 17 is connected tothe head 14 as shown. Guides 18a and 18b are movable within fixed crosssupports 19 to assure the controlled vertical movement of head 14. Asshown in FIG. 2, the guide 18b has an end which when contacted by arms20, 21 limits the position of head 14 in the upper and lower positions.A multi-cam programmer (not shown) controls the operation of cylinder 16to raise and lower head 14 in conjunction with other sequentialoperations of the apparatus 10. Such sequential operations and themovement of the head 14 form no part of the present invention except asmovements of head 14 interrelate with the patch heating apparatus of theinvention.

As shown in FIGS. l-3 the head 14 mounts a yoke consisting of arms 26,27 pivotly connected to the head by a pin 28. Secured at one side of thehead 14 is a cylinder mounting plate 29 which is intermediate the arm 26and the head 14. A spacer 30 separates the mounting plate 29 from thehead 14. A retaining collar fits over the pin 28 outside of arm 26 tosecure together the assembly of yoke arms 26, 27 and head 14. Arm 26 hasat its upper end an actuating pin 31 which is received within clevis 32attached to the actuating rod 33 of cylinder 34. At its upper endcylinder 34 is pivotally mounted within a bracket 36 by means of pin 37,the bracket 36 being attached to the plate 29.

The lower ends of arms 26 and 27 are secured to a heater plate 40 (seeFIG. 3) which mounts a heater element 41. The heater element issinusoidal having ends 42 which have been sprayed with copper todecrease electrical resistance and which are thereafter coated withaluminum oxide for insulating purposes. It will be noted that parallelsections 41a of the heater element are closely spaced and are separatedby very narrow gaps 43 so as to providemaximum radiant heating area andminimum space for the passage of air between respective sections 41a.The heater element 41 is secured to plate 40 along two sides by bars 44and 45. Terminals 46 and 47 provide current through leads 48, 49 to theheater element. A flexible cable 50 is held within tubular bracket 51 tothe plate 40 and encloses the leads 48, 49.

Secured to both the mounting plate 29 and guide member 18a, is ahorizontal actuating arm 53 which receives an adjustable screw 54. Asseen in FIG. 2, when the screw 54 is carried by movement of head 14 andplate 29 from the upper dotted line position to the position of FIG. 2,the lower end 54a of screw 54 will come into contact with a horizontallyslidable stop member 56. The stop member 56 is laterally movable withina groove 55a of block 55 which is attached to plate 52. The plate 52 ismounted upon vertical frame a. The stop member 56 has connected to it apin 57 which rides in a slot 58 in the plate 59 which is movable in avertical direction by cylinder 60. Slots 59a and pins 65 guide verticalmovement of plate 59. The actuation of cylinder 60 is under the controlof the aforementioned multi-cam programmer whose sequential operation issuch that plate 59 moves downwardly to extend stop member 56sufficiently to arrest the downward movement of head 14 by virtue of itsinterconnection with actuating plate 29 and screw 54.

It will be understood that the applicator apparatus 10 includes somemeans for placing the patch 13 in proximity to the lower surface of head14 so that the patch can be held by vacuum pressure thereupon. Thismeans forms no part of the present invention and has not been disclosed.It will be sufficient to say that the patch 13 will be initially held bythe head 14 when the head is in its upper most position, indicatedpartially in FIG. 2 by the dotted line position of members 53,54, and 29which move vertically with the head.

Furthermore, the plate 40 carrying heater element 41 will be moved fromits dotted line position of FIG. 1 into the solid line position of FIGS.1 and 2, preferably immediately after a patch 13 has been received byhead 14. Such movement will take place by actuation of cylinder 34causing clevis 32 to move upwardly and thus effecting rotation of arms26 and 27 about pin 28. Again, movement of plate 40 into its lowerhorizontal position is preferably initiated by the multi-cam programmerwhich controls actuation of cylinder 34.

As soon as the plate 40 has assumed its horizontal position, theprogrammer will actuate the heater element control circuit 60 shown inFIG. 5. The control circuit 60 includes a transformer 61 whose secondaryhas output voltages of 0, 9 volts, 18 volts and 27 volts. The primary isconnected through leads 63 and 64 to a time delay relay 66 havingalternate contact positions with leads 63 and 64. Power to relay 66 is117 volts A.C. as shown through leads 67 and 68. Relay 66 is soconstructed as to permit current to flow initially for say 0.5 second tothe primary of transformer 61 through leads 68, 69 and 67, 64.Consequently the output of transformer 61 to heater element will be 27volts for this initial period, which can be varied for example from 0.25second to 0.75 second. After this initial period, the relay 66 willcause contact to be made between leads 67 and 63 which reduces thevoltage output of the secondary 50 percent, i.e., to 13.5 volts, forapproximately 2 seconds. Relay 66 may be for example of the typemanufactured by the Potter and Brumfield Division of AMF Incorporated,model CLB-51-700l0.

The reason for the operation of the relay 66 is to provide an initialquick heating of element 41 followed by sustained heating for a longerperiod.

After the plate 40 and heating element 41 have been in the solid lineposition of FIGS. 1 and 2 for approximately three seconds, cylinder 34will be actuated to extend clevis 32 and to rotate arms 26, 27 so thatplate 40 assumes its vertical dotted line position. Immediatelyfollowing in sequence, the cylinder 60 will be actuated to urge plate 59downwardly, causing lateral withdrawal of stop member 56 through theagency of pin 57 in slot 58. This permits the head 14 to continue itsinterrupted descent and to apply the patch 13 under pressure to thesubstrate.

The foregoing thus describes a useful addition to patch applicatormachines wherein heat is used to prepare adhesive bonding of a patch toa substrate. The heater element 41 is designed particularly adapted tobe used with applicator heads which hold a patch in place under vacuumsince the interstices between sections 41a of the element are quitenarrow and thus do not permit the passage of substantial amounts ofcooling air in the direction of the head 14.

It will be understood that the foregoing description has been of aparticular embodiment of the invention and is therefore representative.In order to appreciate fully the scope of the invention reference shouldbe made to the appended claims.

We claim:

1. In combination with an apparatus for applying a patch such as asection of hook and loop-type fastener tape and the like to a substratesaid patch having an upper surface and a lower surface coated with anadhesive requiring the application of heat thereto prior to applyingsaid patch to the substrate, said apparatus including a head forgripping the patch along the upper surface thereof, means for movingsaid head between a first position where said head receives the patchand the undersurface thereof is exposed and a second position where saidhead applies pressure against the patch to apply same to the substrate,the improvement comprising a heating element, a yoke mounting saidheating element, means for pivotally connecting said yoke to said head,means connected to said head moving means for selectively rotating saidyoke to selectively interpose said heater element between said head andsaid substrate and for withdrawing said heating element to a positionadjacent to said head, means for selectively arresting movement of saidhead toward the substrate when the heating element is positioned betweensaid head and said substrate to permit the heating elementsimultaneously to apply heat to said patch and said substrate, and forselectively withdrawing said arresting means when said patch and saidsubstrate are sufficiently heated so as to permit said head-moving meansto move said head toward said substrate to its second position and applythe patch against the substrate.

2. The apparatus of claim 1 which includes a reciprocable plate, meansfor moving said plate, a mounting block defining a slot for receiving astop member slidably movable toward and away from the head moving means,said plate defining a slot angularly disposed with respect to said stopmember, a pin attached to said member received within the slot in saidplate whereby reciprocable movements of said plate cause slidingmovement of said stop member, and means connected to said head movingmeans for contacting said stop member when said member is extendedtoward the head moving means, to arrest movement of said head toward thesubstrate and to permit the heating element simultaneously to apply heatto said patch and substrate.

3. The apparatus of claim 2 wherein said head includes vacuum pressuremeans for holding the patch, and said heating element is a flatgenerally sinusoidal combination of sections arranged closely togetherto prohibit substantial passage of air therebetween toward said head.

4. The apparatus of claim 3 wherein electrical circuit means areprovided for directing a large amount of current to said heater elementfor an initial period, followed by a lesser amount of current for alonger period. l

1. In combination with an apparatus for applying a patch such as asection of hook and loop-type fastener tape and the like to a substratesaid patch having an upper surface and a lower surface coated with anadhesive requiring the application of heat thereto prior to applyingsaid patch to the substrate, said apparatus including a head forgripping the patch along the upper surface thereof, means for movingsaid head between a first position where said head receives the patchand the undersurface thereof is exposed and a second position where saidhead applies pressure against the patch to apply same to the substrate,the improvement comprising a heating element, a yoke mounting saidheating element, means for pivotally connecting said yoke to said head,means connected to said head moving means for selectively rotating saidyoke to selectively interpose said heater element between said head andsaid substrate and for withdrawing said heating element to a positionadjacent to said head, means for selectively arresting movement of saidhead toward the substrate when the heating element is positioned betweensaid head and said substrate to permit the heating elementsimultaneously to apply heat to said patch and said substrate, and forselectively withdrawing said arresting means when said patch and saidsubstrate are sufficiently heated so as to permit said headmoving meansto move said head toward said substrate to its second position and applythe patch against the substrate.
 2. The apparatus of claim 1 whichincludes a reciprocable plate, means for moving said plate, a mountingblock defining a slot for receiving a stop member slidably movabletoward and away from the head moving means, said plate defining a slotangularly disposed with respect to said stop member, a pin attached tosaid member received within the slot in said plate whereby reciprocablemovements of said plate cause sliding movement of said stop member, andmeans connected to said head moving means for contacting said stopmember when said member is extended toward the head moving means, toarrest movement of said head toward the substrate and to permit theheating element simultaneously to apply heat to said patch andsubstrate.
 3. The apparatus of claim 2 wherein said head includes vacuumpressure means for holding the patch, and said heating element is a flatgenerally sinusoidal combination of sections arranged closely togetherto prohibit substantial passage of air therebetween toward said head. 4.The apparatus of claim 3 wherein electrical circuit means are providedfor directing a large amount of current to said heater element for aninitial period, followed by a lesser amount of current for a longerperiod.